在胚胎进化过程中,腔位置对外部生殖器进行了相对的转移
Patrick Tschopp1, Emma Sherratt2, Thomas J Sanger2
1Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature
|November 11, 2014
概括
脊椎动物外部生殖器的进化显示出发育起源的转变. 在一些物种中,四肢和生殖器具有共同的发育起点,这表明祖先的四肢起源.
科学领域:
- 发展生物学 发展生物学
- 进化生物学 进化生物学
- 比较解剖学的比较.
背景情况:
- 脊椎动物的陆地化需要在运动和繁殖方面进行适应.
- 翅膀到四肢的过渡已经得到了充分的研究,但外部生殖器的起源仍然不清楚.
- 基因表达的相似性暗示着四肢和生殖器之间的进化联系,但发展机制是未知的.
研究的目的:
- 调查外部生殖器的发育和进化起源.
- 为了确定四肢和生殖器是否共享共同的发育途径.
- 阐明推动生殖器发育多样化的机制.
主要方法:
- 微计算机断层扫描 (micro-CT) 用于高分辨率成像.
- 在三个胚胎类 (,蛇,小鼠) 中追踪血统.
- 用于转录造型的RNA测序 (RNA-seq).
主要成果:
- 外部生殖器的发育已经进化,一些种类表现出四肢和生殖器之间共享的原始体.
- 在状动物中,生殖器从后肢芽生长;在小鼠中,它们从腹部和尾部芽生长.
- 阴道的位置 (生殖器组织中心) 影响了生殖器外生长的细胞招募,并保留了信号反应.
结论:
- 外部生殖器发育的祖先条件很可能是四肢状的.
- 在进化过程中,水的位置发生变化,改变了哺乳动物的生殖器发育.
- 哺乳动物的生殖器发育保留了祖先的肢体分子电路,这是由于共同的进化起源.
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